Detasseling apparatus

ABSTRACT

Apparatus for mechanically removing the tassels from corn plants in a plurality of adjacent rows, the apparatus including a mobile frame adapted to advance along the rows and a plurality of individual detasseling units adjustably carried by the frame for receiving the plants in the adjacent rows and severing the tassels therefrom. Each detasseling unit consists of a housing defining a fore-and-aft passage for receiving the upper portions of the plants, a pair of guide members for directing the plants into the passage, and a circular blade mounted in canted fashion on a transverse shaft extending across the passage. As the shaft is rotated and the unit advanced along the plant row, the blade describes a substantially rectangular swath encompassing the tassel portion of the plants received within the housing, thereby severing the tassels from the plants. The configuration of the housing is such that the leaves of the plants are excluded from the passage and are thus not contacted by the blade.

United States Patent 91 Hansen June 5,1973

I54] DETASSELING APPARATUS Harold Valentine Hansen, Island County,Cordova, Ill.

[75] Inventor: Rock [73] Assignee: Deere & Company, Moline, [1].

[22] Filed: June 30, 1971 [21} Appl. No.: 158,260

609,777 10/1960 ltaly ..56/56 Primary Examiizer-F. Barry Shay AssistantExaminer-J. N. Eskovitz A ttorney-H. Vincent Harsha, Harold M. Knoth,

William A. Murray et al.

[57] ABSTRACT Apparatus for mechanically removing the tassels from cornplants in a plurality of adjacent rows, the apparatus including a mobileframe adapted to advance along the rows and a plurality of individualdetasseling units adjustably carried by the frame for receiving theplants in the adjacent rows and severing the tassels therefrom. Eachdetasseling unit consists of a housing defining a fore-and-aft passagefor receiving the upper portions of the plants, a pair of guide membersfor directing the plants into the passage, and a circular blade mountedin canted fashion on a transverse shaft extending across the passage. Asthe shaft is rotated and the unit advanced along the plant row, theblade describes a substantially rectangular swath encompassing thetassel portion of the plants received within the housing, therebysevering the tassels from the plants. The configuration of the housingis such that the leaves of the plants are excluded from the passage andare thus not contacted by the blade.

9 Claims, 5 Drawing Figures PATENTEDJUH 5191a SHEET 1 [IF 2 I NVENTOR.

HAROLD V. HANSEN ATTORNE FIG.2

PATENTEDJU}! 5 m5 SIIEEI 2 BF '2 FIG.3

. IN VENTOR.

' HAROLD V. HANSEN DETASSELING APPARATUS BACKGROUND OF THE INVENTION Thepresent invention relates generally to croptreating machines, and moreparticularly to apparatus for mechanically detasseling corn plants.

The production of hybrid seedcorn involves thecross-fertilization orpollination of two separate strains or varieties of corn plants, toobtain a third strain possessing the desirable properties of both parentstrains. In actual practice, such cross-fertilization is achieved byplanting a seed-producing field with alternate areas of the two strains,permitting the chosen male strain to cross-fertilize the female strain,and harvesting the latter for seed. Since the corn plant is bisexual, orcontains both the male and female reproductive organs in the form of thetassel and silk, respectively, it is necessary, to preventself-fertilization of the chosen female strain, to remove the tasselportion therefrom before it produces pollen.

The detasseling operation has heretofore been performed almostexclusively with manual labor. Although attempts have been made toproduce a mechanical detasseler, these attempts have not succeeded inproducing a machine capable of severing the entire tassel from the plantwithout materially damaging the leaves and stalk, which at the same timeis capable of highspeed operation and is relatively low in cost. Thedetasseling operation is rather critical in that the entire tassel mustbe removed, to prevent the production of pollen and the resultingself-fertilization of the seed-producing female strain, while at thesame time those portions of the plant adjacent to the tassel must beleft undamaged, to avoid killing or stunting the growth of the plant. Itis in the latter respect that most prior art mechanical detasselers havefailed, since the majority of such devices indescriminately remove theupper portion of the plant.

SUMMARY OF THE INVENTION Accordingly, it is the primary object of thepresent invention to provide mechanical detasseling apparatus capable ofcompletely removing the tassel portion of the plant without damaging theremaining portions thereof. It is a further object to provide suchapparatus that is capable of relatively high-speed operation. It is yeta further object to provide apparatus of the aforesaid character that issimple and economical to manufacture.

The invention comprises, generally, a mobile frame adapted to advancealong parallel rows of corn plants, there being a plurality oftransversely spaced detasseling units adjustably mounted on the frameand adapted to receive the plants in adjacent rows. Each of the units issubstantially identical and comprises a housing having a fore-and-aftpassage for the tassel portion of the plants, guide means for directingthe plants into the passage, and rotary blade means mounted in thepassage to sever the tassels from the stalks. The blade means comprisesa substantially planar, circular blade having a sawtooth edge, the bladebeing mounted in canted fashion on a driven shaft extending transverselyacross the passage defined by the housing. As the unit is advanced alongthe plant row, the blade thus reciprocates transversely in the passage,thereby defining a substantially rectangular swath encompassing thetassels of the plants received by the unit. The housing is formed ofspaced-apart, generally vertical sidewalls, the lower portions of whichconverge downwardly to exclude the upper leaves of the plants from thepassage and thereby prevent the leaves from coming into contact with theblade. Each of the units is mounted on the frame for on-the-goadjustment of its vertical position, to accommodate varying plantheights.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of thepresent invention will be described in conjunction with the accompanyingdrawings in which:

FIG. 1 is a fragmentary front elevation view of the preferred embodimentof the invention;

FIG. 2 is a fragmentary side elevation view of the apparatus taken alongthe line 2--2 of FIG. 1;

FIG. 3 is an enlarged front elevation view of one of the detasselingunits;

FIG. 4 is a side elevation view of a detasseling unit on the same scaleas FIG. 3; and

FIG. 5 is a view taken along the line 55 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the ensuing description,rightand left-hand reference is determined by facing the direction oftravel of the apparatus.

Referring first to FIGS. 1 and 2 of the drawings, the preferredembodiment of the invention comprises a frame structure indicatedgenerally by the numeral 10, the structure being mounted on andextending forwardly from the front portion of an agricultural tractor,shown fragmentarily at 12. The tractor 12 is of the tricycle type,including a front steerable wheel 14 and a pair of rear drive wheels 16(only one being shown) and is constructed to advance along rows ofrelatively tall corn plants, indicated generally by the letter P. Forthis purpose, the tractor includes an elongated, relative high andnarrow body portion 18 and a rear wheel support structure 20 extendingoutwardly and downwardly from the upper rear portion of the body 18,over the tops of the plants P and downwardly between adjacent rowsthereof. The vehicle is driven by an internal combustion enginecontained within an engine compartment 22 in the body 18.

The frame structure 10 comprises a transversely extending member 24supported forwardly of the tractor 12 by means of upper and lower pairsof braces 26 and 28, respectively, the former extending substantiallyhorizontally from the opposite ends of a square tube 30 fixed to the topof the tractor body 18 and secured at their forward ends to the member24, and the latter extending upwardly and forwardly from the oppositesides of the body 18 to the outer end portions of the braces 26.Depending downwardly from the left outer end of the transverse member24, between adjacent rows of plants P, is a vertical support 32.Although only the apparatus to the left side of the tractor is shown inthe drawings, in the preferred embodiment of the invention substantiallyidentical apparatus is included to the right side of the tractor. A pairof upper and lower parallel links 34 and 36 extend rearwardly frombrackets 38 and 40, respectively, on the support 32, to brackets 42 and44, respectively, on a vertical, wheelsupported carriage 46. Thecarriage 46 comprises a vertical, tubular member 48 supported at itslower end by a castor wheel 50, the wheel 50 being rotatably carried ona U-shaped support 52 which, in turn, is received in the lower end ofthe member 48 for free pivotal movement about a substantially verticalaxis. It will be apparent from the structure described that although themember 24 and support 32 are rigidly secured to the tractor 12, thecarriage 46, by virtue of the castor wheel 50 and the connecting links34 and 36, is free to float vertically to follow the contour of theground between plant rows.

Telescopically received in the upper end of the tubular member 48 is amember 54, the vertical position of which is adjustable relative to themember 48 by means of an extensible and retractable hydraulic ram 56acting between a pair of brackets 58 and 60, on the lower end of themember 48 and on the upper end of the member 54, respectively. A supportbracket 62 is fixed to the upper end of the member 54 and, inconjunction therewith, forms a fore-and-aft pair of transverselyextending, substantially square pockets for receiving the inner ends ofdetasseling unit support tubes 64 and 66, respectively. Each of thetubes 64 and 66 carries an identical detasseling unit 68 on its outerend in overlying relation with adjacent rows of plants P. The ram 56 isoperable by conventional means to raise and lower the member 54 andthereby adjust the vertical position of the units 68 relative to theplants P, as the tractor 12 advances along the rows. Each of the supporttubes 64 and 66 contains a plurality of transversely spaced verticalapertures in its inner end which may be selectively aligned withapertures in the top and bottom walls of the support bracket 62 toadjust the lateral position of the unit 68 and to thereby accommodatedifferent row spacings. A pair of releasable fasteners such as bolts 70are employed to retain each of the tubes 64 and 66 in their desiredpositions.

Referring now to FIGS. 3-5 which illustrate a detasseling unit 68 ingreater detail, it will be seen that the unit comprises a housingstructure formed of a substantially horizontal top wall 72 secured tothe bottom wall of the tube 64, and a pair of left and right spacedsidewalls 74 and 76, respectively, depending downwardly and inwardlyfrom the opposite longitudinal edges of the wall 72. The walls 72, 74and 76 conjunctively define a fore-and-aft passage 78 for the tasselportion T of the corn plant P. As illustrated best in FIG. 3, the lowerportions 80 and 82 of the walls 74 and 76, respectively, convergedownwardly and act as shields to exclude the leaves L on the upperportion of the plant P from the passage 78.

A pair of L-shaped guide rods, having vertical portions 84 andhorizontal portions 86, are positioned on opposite sides of the housingstructure and forwardly thereof to guide the plants into the passage 78as the apparatus is advanced along the plant row. The upper ends of thevertical portions 84 are received in vertically apertured cylindricalmembers 88 and are adjustably retained therein by means of setscrews 90,the members 88 being mounted on the outer ends of horizontal supportrods 92 which, in turn, are fixed to and diverge forwardly from the topwall 72 of the housing. The setscrew adjustment permits both the heightand the horizontal angle of the guide rod portions 86 to be adjusted tobest suit the type of corn plant being detasseled.

Rotatably supported in bearings 94 and 96 in the walls 74 and 76,respectively, and extending transversely across the. passage 78 definedthereby is a shaft 98 having a substantially planar and circular blade100 affixed centrally thereto. A conventional hydraulic motor 102,supplied with hydraulic fluid under pres sure from a source on thetractor 12, is operable to rotate the shaft 98 and thus the blade 100,in the direction indicated in FIG. 4. The axis of the shaft 98intersects the center of the blade 100 and, as shown in FIG. 3, theplane of the blade forms an oblique angle with the shaft axis. As theshaft 98 is rotated, the blade 100 thus wobbles or reciprocatestransversely within the housing, the extreme alternate position thereofbeing indicated with a dashed line at 101 in FIG. 3. As the apparatus isadvanced forwardly along the plant row, the blade thus describes asubstantially rectangular swath in a vertical plane extendingtransversely across the row, the outline of the swath being indicatedwith a dashed line at 104 in FIG. 3. The outer circular edge of theblade 100, as shown in FIG. 5, is provided with a plurality of sharpteeth 106. As the edge of the blade reciprocates rapidly across theupper portion of the plant contained within the passage 78, the tassel Iis thus engaged by the teeth 106 and is severed from the stalk anddischarged outwardly and rearwardly therefrom. It will be apparent thatproper operation of the apparatus requires that the rearward velocity ofthe outer periphery of the blade 100 beneath the shaft 98 besubstantially greater than the forward velocity of the tractor 12.

Although as previously noted the downwardly converging configuration ofthe sidewall or shield portions and 82 acts to exclude the upper plantleaves L from the passage 78, if a leaf should enter the passage, thenarrowness of the swath 104 described by the blade reduces thelikelihood of the leaf coming in contact with the blade. And, shouldsuch contact be made, the reciprocating action of the blade will tend todeflect the leaf to one side while inflicting minimum damage thereto.

t In operation, the units 68 are adjusted transversely by means of thebolts 70 retaining the tubes 64 and 66 in the support bracket 62, sothat the transverse spacing of the units conforms with the row spacingof the field to be detasseled, and are adjusted vertically by means ofthe hydraulic ram 56, so that the swath 104 described by the blades 100coincides with the tassel portions T of the plants P. The blades 100 arethen rotated rapidly by means of the hydraulic motors 102, and thetractor is advanced along the rows of plants. As previously indicated,the guide rod portions 86 direct the tassel portion of each succeedingplant in the row into the passage 78 defined by the housing structure,and the action of the blade 100 contained therein severs the tassel fromthe stalk. The vertical position of the unit 68 may be adjusted on thego by means of the hydraulic ram 56, to accommodate varying plantheights within the field.

I claim:

1. Corn detasseling apparatus comprising: mobile frame means adapted toadvance along a row of corn plants; fore-and-aft extending, invertedU-shaped structure mounted on the frame means and defining a downwardlyopening fore-and-aft passage for the tassel portion of the plants, saidstructure including a top and a pair of fore-and-aft extending,downwardly converging generally planar sides for excluding leaves of theplants from the passage; guide means engageable by the plants to guidethe tassel portions thereof into the passage as the apparatus isadvanced along the row; and blade means mounted within the passage tosever the tassels from the plants.

2. The invention defined in claim 1 wherein said blade means isrotatable about an axis extending substantially transversely across thepassage.

3. The invention defined in claim 2 wherein said blade means issubstantially planar and forms an oblique angle with said axis.

4. The invention defined in claim 3 wherein said blade means issubstantially circular and is intersected substantially at its center bysaid axis.

5. Corn detasseling apparatus comprising: mobile frame means adapted toadvance along a row of corn plants; housing means mounted on the framemeans and having transversely opposed side walls defining a fore-and-aftpassage for the tassel portion of the corn plants, the lower portions ofthe side walls extending downwardly and inwardly to exclude leaves ofthe corn plants from the passage; guide means for guiding the tasselportion of the corn plants into the passage defined by the walls of thehousing means; a shaft rotatably supported on the side walls of thehousing means and extending substantially transversely therebetween;impact cutting blade means mounted on the shaft and extending into thatportion of the fore-and-aft passage lying between the downwardly andinwardly extending portions of the sidewalls, said blade means beingintersected by the axis of the shaft and forming an oblique angletherewith, whereby said blade means reciprocates transversely in thatportion of the passage lying between the lower portions of the sidewallswhen the shaft is rotated, and is thereby operative to impact the tasselportion of the plants; and means for rotating said shaft at a sufficientvelocity so that the impact of the blade on the tassel removes thelatter from the plants.

6. Corn detasseling apparatus comprising: mobile frame means adapted toadvance along a row of corn plants; structure mounted on the frame meansand defining a fore-and-aft passage for the tassel portion of saidpassage, the lower terminal edges of said sides defining the edges of afore-and-aft opening through which the upper stalk portions of theplants pass as the apparatus is advanced along the row, the inclined,downwardly converging sides being operative to exclude plant leaves fromthe passage; and blade means mounted within the passage between theconverging sides to sever the tassel portion from the plants.

7. The invention defined in claim 6 including a shaft rotatablysupported on at least one of said sides and extending transversely inthe fore-and-aft passage, said blade means being mounted on said shaftfor rotation therewith.

8. The invention defined in claim 7 wherein said blade means comprises asubstantially circular, planar blade having a plurality of teeth formedabout its peripheral edge and connected at its center to said shaft toform an oblique angle therewith, whereby said blade reciprocatestransversely in the passage as the shaft is rotated and is operative tosever the tassel portion from the plants.

9. For use in corn detasseling apparatus having a mobile frame adaptedto advance along a row of corn plants, a detasseling unit comprising: afore-and-aft extending, inverted U-shaped housing structure adapted forattachment to the frame and defining a fore-and-aft passage for thetassel portion of the plants, said housing shaft means rotatablysupported on at least one of the side walls of the housing structure andextending transversely in the fore-andaft passage defined by thehousing; and cutting means connected to the shaft for rotation therewithin the passage, said cutting means being operative to engage the tasselportion of the plants moving through the passage and to sever saidtassel portion from the plants.

1. Corn detasseling apparatus comprising: mobile frame means adapted toadvance along a row of corn plants; fore-and-aft extending, invertedU-shaped structure mounted on the frame means and defining a downwardlyopening fore-and-aft passage for the tassel portion of the plants, saidstructure including a top and a pair of fore-and-aft extending,downwardly converging generally planar sides for excluding leaves of theplants from the passage; guide means engageable by the plants to guidethe tassel portions thereof into the passage as the apparatus isadvanced along the row; and blade means mounted within the passage tosever the tassels from the plants.
 2. The invention defined in claim 1wherein said blade means is rotatable about an axis extendingsubstantially transversely across the passage.
 3. The invention definedin claim 2 wherein said blade means is substantially planar and forms anoblique angle with said axis.
 4. The invention defined in claim 3wherein said blade means is substantially circular and is intersectedsubstantially at its center by said axis.
 5. Corn detasseling apparatuscomprising: mobile frame means adapted to advance along a row of cornplants; housing means mounted on the frame means and having transverselyopposed side walls defining a fore-and-aft passage for the tasselportion of the corn plants, the lower portions of the side wallsextending downwardly and inwardly to exclude leaves of the corn plAntsfrom the passage; guide means for guiding the tassel portion of the cornplants into the passage defined by the walls of the housing means; ashaft rotatably supported on the side walls of the housing means andextending substantially transversely therebetween; impact cutting blademeans mounted on the shaft and extending into that portion of thefore-and-aft passage lying between the downwardly and inwardly extendingportions of the sidewalls, said blade means being intersected by theaxis of the shaft and forming an oblique angle therewith, whereby saidblade means reciprocates transversely in that portion of the passagelying between the lower portions of the sidewalls when the shaft isrotated, and is thereby operative to impact the tassel portion of theplants; and means for rotating said shaft at a sufficient velocity sothat the impact of the blade on the tassel removes the latter from theplants.
 6. Corn detasseling apparatus comprising: mobile frame meansadapted to advance along a row of corn plants; structure mounted on theframe means and defining a fore-and-aft passage for the tassel portionof the plants, said structure including a pair of fore-and-aftextending, generally planar sides inclined downwardly and inwardly in avertical plane transverse to said passage, the lower terminal edges ofsaid sides defining the edges of a fore-and-aft opening through whichthe upper stalk portions of the plants pass as the apparatus is advancedalong the row, the inclined, downwardly converging sides being operativeto exclude plant leaves from the passage; and blade means mounted withinthe passage between the converging sides to sever the tassel portionfrom the plants.
 7. The invention defined in claim 6 including a shaftrotatably supported on at least one of said sides and extendingtransversely in the fore-and-aft passage, said blade means being mountedon said shaft for rotation therewith.
 8. The invention defined in claim7 wherein said blade means comprises a substantially circular, planarblade having a plurality of teeth formed about its peripheral edge andconnected at its center to said shaft to form an oblique angletherewith, whereby said blade reciprocates transversely in the passageas the shaft is rotated and is operative to sever the tassel portionfrom the plants.
 9. For use in corn detasseling apparatus having amobile frame adapted to advance along a row of corn plants, adetasseling unit comprising: a fore-and-aft extending, inverted U-shapedhousing structure adapted for attachment to the frame and defining afore-and-aft passage for the tassel portion of the plants, said housingstructure having opposed, generally planar side walls convergingdownwardly and terminating in transversely spaced, fore-and-aftextending edges defining a fore-and-aft opening for the upper stalkportions of the plants, the downwardly converging side walls beingoperative to exclude the leaves of the plants from the fore-and-aftpassage defined by the housing structure; shaft means rotatablysupported on at least one of the side walls of the housing structure andextending transversely in the fore-and-aft passage defined by thehousing; and cutting means connected to the shaft for rotation therewithin the passage, said cutting means being operative to engage the tasselportion of the plants moving through the passage and to sever saidtassel portion from the plants.